That’s exactly what this fellow needs! Cheers to you Dunc!!
If you bought all this from a dealer he should install it free of charge to your full satisfaction. Building a positive relationship with him over time will make sure you get the best from your system. The LP12 set up is probably the most crucial thing to get right here.
There is a technical reason Phil Budd (Linn speaker designer) likes what they state in the manual (can’t recall what it was) but, in terms of musicality, myself and quite a few Linn owners prefer connecting to the tweeter inputs instead, but have a listen yourself and see which you prefer. There’s not much in it to be fair.
I just remembered, if you find the 140 bass too much then there is a modification you can make to cut bass output by 2db. It would have been done by your dealer back in the day (if required) but not difficult to do yourself.
I seem to recall the idea being that in standard form they would work better in wood constructed homes as often found in the US and Scandinavia. Whereas, a typical UK brick-built house might need the cut to bring down bass output. Mine sounded better (both presentation and musicality) with the 2db cut.